The United States are trimming their captain's selections for the 2014 Ryder Cup from four to three players, captain Tom Watson has said.

"Giving our players one more opportunity to earn a spot on merit, I believe, is the right thing to do," Watson told the official Ryder Cup website.

Watson will take the top nine players from the Ryder Cup standings and make his three picks ahead of the 40th match at Gleneagles in Scotland from September 26-28.

"I will use all possible resources in choosing these three captain's choices to complete the best possible team in order to win the Cup back for the United States," Watson added.

The US switched to four captain's picks for the biennial golf match against Europe in 2008.

The points race to determine the 2014 team begins on April 14 after this year's US Masters.

Eight-times major winner Watson will lead his players into the match against a European team captained by Ireland's Paul McGinley.

Watson's decision came as a surprise to US Ryder Cup stalwart Tiger Woods, who will have a chance to reclaim the world No 1 ranking on Sunday (local time) with victory at the Arnold Palmer Invitational.

"I don't know what that was about," Woods told reporters after the tournament's Pro-Am.

"I just heard about it on the golf course today.

"I didn't hear the reasoning behind it, I just heard it went from four to three."

Europe's team has included either two or three captain's picks in recent Ryder Cups.